Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 20 for “"Noise propagation"”.
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Signal and noise propagation in genetic circuits
… and cellular memory. Accurately predicting noise propagation in gene networks is thus crucial for reverse engineering natural networks and designing reliable synthetic genetic circuits. To determine how noise propagates through gene networks we measure, in single bacterial cells, expression …
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Quantum noise propagation in nonlinear optical media
Good quantum mechanical descriptions of noise evolution with propagating optical waves are critical to understanding the processes which currently limit the generation of squeezed radiation in nonlinear materials. In the first part of this dissertation a general quantum optical model is developed …
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Numerical investigation of air vehicle noise propagation effects
… part of this environmental impact is the noise emitted by air vehicles, which is considered rather significant for community annoyance. The generation and propagation of air vehicle noise are two different areas of interest, which require accurate prediction in order to control the emitted …
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Predicting fan noise propagation in aeroengine bypass ducts
… thesis explores the prediction of rearwards fan noise propagation within the bypass duct and its radiation into the far feld. Two recently developed models: B-induct and GXMunt, are exploited in application to real engine bypass ducts and their performance is evaluated. These methods are an …
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A computer model to simulate suburban noise propagation
Thesis. 1978. M.S. cn--Massachusetts Institute of Technology. Dept. of Mechanical Engineering.
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Modeling Of Atmospheric Refraction Effects On Traffic Noise Propagation
Traffic noise has been shown to have negative effects on exposed persons in the communities along highways. Noise from transportation systems is considered a nuisance in the U.S. and the government agencies require a determination of noise impacts for federally funded projects. There are several …
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Noise propagation model for the design of weather specific noise abatement procedures
This thesis presents an aircraft noise prediction simulation that incorporates actual weather in flight dynamics and noise propagation. The rapid prototyping simulation environment NOIse SIMulator (NOISIM) includes a sound propagation model based on a ray tracing algorithm that incorporates …
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SOI Circuit Design Styles and High-Level Circuit Modeling Techniques
Cell-based noise analysis tools. In advanced SOI technologies, the input noise may propagate, with little attenuation, through several or many gates. Therefore, accurately modeling noise propagation (from a cell's inputs to its outputs) is of significant importance for cell-based noise analysis …
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Allocating decoupling capacitors to reduce simultaneous switching noise on chips
L dI/dt noise due to simultaneous switching of circuits on chips is a growing problem in VLSI design. This kind of noise can lead to timing errors and significant circuit slowdowns, if not kept within reasonable bounds. The most common way of reducing this form of noise is the addition of …
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The Effect of Blade Aeroelasticity and Turbine Parameters on Wind Turbine Noise
… Therefore, the prediction of large wind turbine noise over long distances is critical. The wind turbine noise prediction is a very complex problem since it has to account for atmospheric conditions (wind and temperature), ground absorption, un-even terrain, turbine wake, and blade deformation. In …
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Very low frequency seismo-acoustic noise below the sea floor (0.2-10 Hz)
Ambient noise in the sea has been observed for over 100 years. Previous studies conclude that the primary source of microseisms is nonlinear interaction of surface gravity waves at the sea surface. Though this source relationship is generally accepted, the actual processes by which the wave …
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Acoustic optimisation and prediction of sound propagation in turbofan engine ducts
… in this thesis explores the prediction of noise propagation and<br/>radiation in turbofan engine intakes and bypass ducts, and the optimisation of noise attenuation<br/>by using acoustic liners. A commercial FE/IE code ACTRAN/TM is used<br/>within two shell programs; B-induct for bypass …
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Prediction of Tonal Acoustic Radiation Due to Feedback-Loop Resonant Interactions in Transitional Airfoils
… surface integral methods to study the far-field noise propagation from the flow acoustic resonant interactions of the transitional airfoil. The Potential-Theoretic Method (PTM) as an advancement to traditional Kirchhoff methods is presented. The PTM eliminated the need to calculate the normal …
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Frequency Domain Conductive Electromagnetic Interference Modeling and Prediction with Parasitics Extraction for Inverters
… the EMI spectrum directly by decomposing noise sources and their propagation paths. This method not only largely reduces the computational effort, but also provides the insightful information about the critical components of the EMI generation and distribution. The study was first applied …
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Coupling of Structural Dynamic and Acoustic Analyses Using the FEM and BEM
<p>Noise from structural vibration is a major consideration in the design and manufacturing of a product, such as an automobile, airplane, and other consumer goods. Acoustic simulation is an important step to optimize the performance of many new products early in the design stage rather than …
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Electromagnetic Interference and Compatibility within SiC-based Medium Voltage Converters
… even more difficult. Unlike converter-level noise emissions which can be regulated by certain EMI/EMC standards, the noise inside the power converter has no standard to follow. Moreover, even if a converter complies with certain standards at its terminals, the internal components are not …
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Passive Component Weight Reduction for Three Phase Power Converters
… The second approach focuses on reducing the EMI noise generated from the converter using a three-level and/or interleaving topology and changing the modulation and control methods to reduce the noise source and reduce the weight and size of the filters. This dissertation is divided into five …
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Utilizing Distributed Vibration Absorbers to Reduce Noise Transmission Through the Windshield of a Cessna 150
High levels of noise have historically been present in the interior of aircrafts. This causes passenger, pilot, and other aircraft employee fatigue as well as speech interference and discomfort issues. In general aviation aircraft, little has been done to reduce the noise in the interior of …
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Numerical investigation of slat noise attenuation using acoustic liners
Noise generated by high-lift devices such as slats on a wing is a major contributor to the overall airframe noise during the landing approach of a commercial aircraft. In this work the concept of attenuating slat noise using absorptive acoustic liners in the slat/main element gap is explored using …
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Distributed Feedback Control Algorithms for Cooperative Locomotion: From Bipedal to Quadrupedal Robots
… distributed QPs have reduced sensitivity to noise propagation when compared with the centralized QP. Finally, to demonstrate that the resultant distributed QP-based nonlinear control algorithm translates equivalently well to hardware, an extensive set of blind locomotion experiments on the A1 …